Abstract

This thesis argues that party ideologies are made up of a series of issues that vary in the extent of their interconnections. This approach to party programmes builds on Converse's (1964) description of belief systems and on Downs' (1957) understanding of ideologies. The concept of policy interconnections, originally applied to voter preferences, can also be used to understand party ideologies. In fact, parties are likely to exhibit stronger interconnections than voters. The strength, nature and effect of policy interconnections are examined for 23 Western European and English-speaking democracies using two expert surveys and the dataset of the Comparative Manifesto Project. Three distinctions need to be made in order to understand how party policies are interconnected. First, linkages between issues are based either on an inherent logic or on historical and sociological circumstance. Logic-based interconnections are more consistent across contexts than circumstance-based interconnections. Moreover, parties are more likely to alter policy stances on two areas simultaneously if the issues are linked through logic. Second, linkages exist for position and salience, but salience interconnections are weaker than their positional counterparts. This helps explain the strategic attraction of salience manipulation. Finally, positions can be more extreme or more moderate than the overall mean party preferences, a characteristic termed the 'degree of unusualness'. Parties are likely to stress such unusual positions, especially if they are small, niche competitors. The findings of this thesis have important implications for the study of party competition. For example, strategies such as vote-maximization and salience manipulation are directly affected by the impact of policy interconnections. This approach therefore significantly extends existing spatial models of party competition and challenges some of their assumptions. As interconnections influence voter choice and coalition formation, there are also broader implications for political representation.